detail: brick veneer homes
disconnecting the wall cavity
The thermal performance of timber floors
in brick veneer construction can be readily improved by
eliminating the cavity airflow path at either the roof
A 'flashing' across the wall cavity controls the airflow
between the roof space and sub-floor, effectively disconnecting
the roof space from the sub-floor space.
This change will
directly improve the House Energy Rating of a design with
an enclosed sub-floor by at least 0.6 Star.
Make the change
in either the roof or sub-floor area by taking flashing
from the brickwork to the top- or bottom-plate. With the
bottom-plate option you will need to insert weep holes
for removing condensation – as with slab on ground construction.
Another way is to fold over and secure foil
across the cavity gap at the top of the brickwork.
of floor insulation, especially for cool zones, is looking
at restricting air-flow in the sub-floor space, by enclosing the
area while still allowing enough air movement for healthy ventilation.
In more temperate zones being off
the ground has the advantage of helping the house cool
quicker if air can move freely underneath, as in the traditional
Queenslander house model.
To learn more, read the FWPRDC
solutions to enhance the thermal resistance of suspended
timber floor systems in Australia. 1.26 MB
For information on adequate vents and sensible floor vent placement,
see Building Code of Australia Volume 2 Part 3.4.1.